How to find the file and path of a function in shell?

I run a command in my linux server typing run_mysql. I firstly thought it was an alias, but when I typed the command type run_mysql it showed me it is a function. However the path to the file where this fucntion is supposed to be was not presented. My question is how can I find where this function is defined. Do you have any command I can use? (I also tryed declare -F, find, locate,etc and had no success).